Up until just a couple of days ago, I would have probably said no, but I can now say a definite "yes", it's possible for FS2004 to send data at a much higher rate than the visual frame rate.
I spent some time this weekend implementing this great feature where users would get warning messages in the chat window when their data rate was above a specified limit. After a number of warnings, they'd get kicked. Trouble is that I then discovered that when FSHost kicks someone and they reconnect, they still have the first server player in their chat list, so now they have two of them. I've seen this before and never knew why it happened, but I also never really worried about it too much. The problem is that FS2004 still sees both of these server players as real players, even though they have the same IP address. So it happily sends all of its location data to BOTH of the server players, and the server ends up getting data at a rate that's twice the visual frame rate. If the player gets kicked again and reconnects, he'll have 3 server players in the list, and the server will receive data at 3 times the visual rate. And then 4, 5, etc.

The really confusing thing is that this doesn't happen when FS itself is hosting the session -- only when FSHost hosts it. I spent quite a while tracing out the DirectPlay messages that FS sends when it kicks someone vs. the messages that FSHost sends, and they're absolutely identical. I have no idea what's causing the problem.
And to make it worse, I had to remove the whole feature from 3.1 beta 27 after all that hard work, because short of restarting their FS, there's nothing the user can do to fix it on his end

Suggestions welcome on this one... what a mess.
Russell